Optimization of sintering conditions in bulk MgB2 material for improvement of critical current density

M. Muralidhar, K. Nozaki, H. Kobayashi, X. L. Zeng, A. Koblischka-Veneva, M. R. Koblischka, Kazuo Inoue, Masato Murakami

研究成果: Article査読

40 被引用数 (Scopus)


The present investigation focuses on methods to further improve the Jc values of disk-shaped bulk MgB2 superconductors by optimizing the sintering conditions. We prepared two sets of bulk MgB2 material from commercial high-purity powders of Mg metal and amorphous B using a single-step solid-state reaction process. To optimize the sintering time, a set of samples was sintered at 775 °C with sintering duration ranging between 1 and 10 h (pure Ar atmosphere). A second set of samples was produced similarly at 775, 780, 785, 795, 800 and 805 °C (3 h, pure argon atmosphere). X-ray diffraction analysis showed that both sets of samples were single phase MgB2. Magnetization measurements confirmed a sharp superconducting transition with Tc,onset ≈ 38.2 K-38.8 K. The critical current density (Jc) values for MgB2 samples produced for 1 h were the highest in all processed materials, i.e., the high Jc value of 270,000 A/cm2 and 125,000 A/cm2 (20 K, self-field and 1 T) were achieved in the sample produced at 775 °C, without any additional doping. In contrast, the second series of samples clearly indicated that at 805 °C (3 h) the highest Jc of 245,000 A/cm2 and 110,000 A/cm2 (20 K, self-field and 1 T) were achieved. AFM and EBSD observations indicated that largest amount of fine grains do exist in the sample sintered at 775 °C, but the narrowest distribution of grains does exist in the sample sintered at 800 °C. The present results clearly demonstrate a strong relation between the microstructure and the pinning performance. The optimization of the sintering conditions is crucial to improve the performance of bulk MgB2 samples.

ジャーナルJournal of Alloys and Compounds
出版ステータスPublished - 2015 8月 3

ASJC Scopus subject areas

  • 材料力学
  • 機械工学
  • 金属および合金
  • 材料化学


「Optimization of sintering conditions in bulk MgB2 material for improvement of critical current density」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。